This usually means the normal startup volume is probably also damaged, which may be why you’re trying to boot from an external to begin with. When that happens, the usual cause is that the Mac’s startup device has been damaged in such a way as to prevent the hidden recovery volume from being accessible. There’s an alternate method for accessing the recovery volume should the above method fail. Jump ahead in the instructions to Using the Startup Security Utility Use Internet Recovery Once the Apple logo is present, you can release the keyboard shortcut.Īfter a brief wait, you should see the macOS Utilities desktop appear. The Recovery desktop with macOS Utilities window open. If you’re using a Bluetooth wireless keyboard, you may need to start up your Mac and wait to hold down the keyboard shortcut until after you hear the startup chime. Continue to hold down the keyboard shortcut until you see the Apple logo. Once the Mac is off, hold down the Command and R keys (⌘ + R) while starting up your Mac. For most of us, accessing the recovery volume and it’s Security Startup Utility is just a keyboard shortcut and a restart away. The Security Startup Utility is part of the macOS Recovery volume that is hidden on the Mac’s startup drive. Apple provided the Startup Security Utility so that a user with administrator privileges can alter the default security settings. Since our goal here is to boot from an external device, the settings for the T2 security chip will need to be changed. It also prevents booting from external devices that someone may connect to your Mac. The T2 chip helps protect your Mac against unauthorized access by providing a secure boot environment that ensures the Mac only boots from an authorized (signed) version of the Mac OS. If your Mac includes a T2 security chip, there are a couple of additional steps you’ll need to perform to allow your Mac to start up from an external device. How to Enable a T2-Equipped Mac to Boot From an External Device Although the ports appear the same, the speed at which they operate can be significantly different.

How to check startup disk space on mac